For first time, doctors communicate with patient in persistent vegetative state

A 23-year-old woman who has been in a vegetative state since suffering devastating brain damage in a traffic accident has stunned doctors by performing mental tasks for them. Brain scans revealed that the woman, who has shown no outward signs of awareness since the accident in July last year, could understand people talking to her and was able to imagine playing tennis or walking around her home when asked to by doctors.

The discovery has astounded neuroscientists who believe it could have dramatic implications for life and death decisions over other patients diagnosed as being in a persistent vegetative state (PVS). Last year, an intense legal battle over the life of Terri Schiavo, a woman diagnosed as PVS, was brought to an end when US courts upheld the decision to remove her feeding tube in March. She died 13 days later in a Florida care home.

Neuroscientists at the Medical Research Council's cognition and brain sciences unit at Cambridge and the University of Liege in Belgium used a brain scanning technique called functional magnetic resonance imaging (fMRI) to detect signs of awareness in the woman, the first time scientists have been able to do so in a PVS patient. The technique is now likely to become a standard way of determining how conscious vegetative patients are.

"This is extremely important. It's the difference between life and death. From cases in the UK and the US, we know that end-of-life decisions are of course extremely important and this will definitely change the way we deal with these patients. When you have signs of consciousness, you cannot decide to stop hydration and nutrition," said Steven Laureys, a neurologist at the University of Liege and co-author of the study which appears in the journal Science today.

Researchers led by Adrian Owen at Cambridge University began tests on the woman five months after her accident. Although she had emerged from a coma, she was diagnosed as being in a vegetative state, in which patients enter a cycle of sleeping and waking and even open their eyes, but are completely unresponsive.

Scientists ascertained that the woman could understand speech by playing a variety of sentences. Using the fMRI scanner, which takes snapshots of brain activity every second or two, they spotted different parts of her brain lighting up depending on which sentence she heard.

Previous attempts to spot signs of awareness in PVS patients have been inconclusive because brains can respond to some actions automatically. The uncertainty forced the scientists to come up with a test that would show categorically whether the patient was conscious or not.

Dr Owen said: "We said to her, when you hear the word 'tennis', we want you to imagine being on the centre court of Wimbledon playing a big rally and every time the ball comes to you, you struggle to get it back. Then, we had a second scenario in which we wanted her to imagine going from room to room in her home."

The two scenarios were chosen to trigger activity in different parts of her brain so they would be picked up by the scanner. While thinking about tennis, the scientists hoped to see a part of the brain called the premotor cortex, which governs limb movement, flicker into life. If she thought about walking around her flat, they expected to see a brain region called the parahippocampal gyrus, which handles mental maps of places, light up.

During the scans, the scientists said the words "tennis", "home" or "rest" every 30 seconds and looked for changes in her brain activity. Remarkably, after each word, her brain lit up as expected, suggesting she was responding to the instructions. Further tests showed her brain activity was indistinguishable from that of healthy volunteers doing the same task.

Scientists now have to discover how common it is for others in a vegetative state to be similarly aware of their surroundings. The woman in the study has since been able to follow her own reflection in a mirror, leaving open the possibility the brain scans may simply have picked up very early signs of her recovery.

Dr Owen added that the technique had shortcomings in helping diagnose patients, as some may not hear or understand the questions during a scan. "This gives us one more tool for making those very difficult decisions," he said.

Professor Colin Blakemore, neuroscientist and director of the Medical Research Council, said: "This is very impressive evidence for what continues to function in the brain, but function doesn't mean awareness or even potential for awareness. This is a strong indication that it is worth continuing to find ways of raising conscious awareness in such patients, because this work suggests the brain is still capable of cognitive function."

Explainer: PVS

Persistent vegetative state was first described in 1972 by Scottish and American neurologists and only came to medical attention because of extraordinary advances in keeping severely brain-damaged patients alive for longer.

Neurologically, the condition is a slight improvement on a coma. Patients diagnosed as PVS show no signs of consciousness or awareness, but unlike those in a coma, have periods of sleep and wakefulness and periodically open their eyes.

The condition is a source of huge controversy in medical and legal fields, largely because of the difficulty in proving a patient is unaware and the extreme difficulty in predicting whether a patient will ever recover.

Adults typically have a 50% chance of recovering from a persistent vegetative state within the first six months, but after a year, the chances of recovery drop dramatically. Those who recover after longer periods usually experience serious disabilities.

The mysterious condition continues to confound scientists. In May, a team of British and South African doctors announced they had given sleeping pills to a PVS patient to help calm restless movements at night. The patient woke up 15 minutes later and was able to speak and even tell jokes.

Doctors have kept the patient on the pills, and believe it works by acting on part of the brain that had been shut down in response to the patient's original trauma.